//75.颜色分类
class Solution {
     public void swap(int[] nums,int i,int j){
            int t = nums[i];
            nums[i] = nums[j];
            nums[j] = t;
        }
    public void sortColors(int[] nums) {
       int left = -1;
       int right = nums.length;
       int i = 0;
       while(i < right){
        if(nums[i] == 0){
            swap(nums,++left,i++);
        }else if(nums[i] == 1){
                i++;
        }else{
            swap(nums,--right,i);
        }
       }

        
    }
}